OLYMPIA - With thousands of sea lions moving into state waters as part of their fall migration, the Washington Department of Fish and Wildlife (WDFW) is cautioning people to give the animals a wide berth if they encounter them on the beach.

Dogs and horses should also be kept clear of sea lions, said Dyanna Lambourn, a WDFW wildlife biologist specializing in marine mammals.

"Sea lions are easily provoked and surprisingly quick, even on the beach," said Lambourn, noting that male California sea lions often weigh up to 800 pounds. "Even sick animals can suddenly become aggressive."

From late summer to early fall, 4,000 to 5,000 California sea lions migrate north, mingling with native Steller sea lions along the Washington coast, she said.

Since August, 23 sea lions have been reported stranded on beaches from Long Beach to Everett, Lambourn said. Most of the beached animals were sick, Lambourn said, noting that six sea lions tested here this year had leptospirosis, a bacterial disease that can spread to humans and domestic animals through exposure to bodily fluids.

Although there are no cases on record of a person contracting leptospirosis from a sea lion, Lambourn advises people to avoid contact with any dead or dying marine mammal and to keep pets away to minimize potential exposure to any diseases the animals may harbor.

Anyone who encounters a beached sea lion is asked to call the Northwest Marine Mammal Stranding Network at 1-206-526-6733, ext. 1. Staffed by state and federal biologists with help from volunteers, the phone line is monitored daily, including weekends and holidays. People who make a report are asked to provide their name and phone number as well as the location, size and description of the animal and its condition.

"Most people who see a sea lion or another marine mammal on the beach just want to make sure the animal gets the attention it needs," Lambourn said. "Calling the Stranding Network is the best way to accomplish that."